Talk of the Nation on KAZU

Historian Noah Andre Trudeau is known for uncovering secrets of the Civil War. His previous books, Bloody Roads South and Gettysburg, have unveiled information about Gen. William Tecumseh Sherman's march to the sea in 1864, and the legacy of Confederate Gen. Robert E. Lee. Now, in preparation for a book about a largely unexamined period of President Abraham Lincoln's life, Trudeau is in search of witnesses.

The remaining GOP presidential candidates, Mitt Romney, Rick Santorum, New Gingrich and Ron Paul, are all fighting to sell a slightly different brand of conservatism. The definition of what it means to be conservative has changed over the years.

After a loved one dies, it's becoming more common to offer and receive condolences through a Facebook post or an email. New York Times contributor Bruce Feiler discusses the new customs that are evolving to guide the grieving process in the digital age.

President Barack Obama's campaign has urged top donors to support a super PAC run by former Obama aides. The president previously called the fundraising groups a "threat to democracy." The Center for Responsive Politics' Sheila Krumholz discusses the shift and NPR's Ken Rudin reviews the week in politics.

Many mid- and large-sized companies rely on computerized systems to scan resumes and narrow the field of job candidates. Some tracking software may overlook qualified applicants who haven't used the right keywords. The Wall Street Journal's Lauren Weber explains what it takes to get noticed.